316L/Q235、316L/700L轧制复合板抗氢性能研究
Study on hydrogen embrittlement resistance of 316L/Q235 and 316L/700L rolled composite plates
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摘要: 低成本不锈钢复合板不仅具有不锈钢的高抗氢性能,还具有高强度、耐磨等低合金钢的优点,这为开发优异抗氢性能的商业材料提供了新的视角。但是,就不锈钢/碳钢复合板而言,覆层微观结构对其抗氢性能的影响还不明确。因此,设计了不同变形抗力的基材(Q235、700L)来调控覆层的微观结构。研究了316L/Q235、316L/700L复合板不锈钢层、碳钢层的微观组织及其对复合板抗氢性能的影响。结果表明:对于316L/700L复合板,覆层316L不锈钢层优先再结晶,其氢脆敏感性指数由316L/Q235复合板的 9.8%降至5.9%。通过调控复合板两种材料的再结晶行为,316L/700L复合板覆层316L不锈钢的∑3孪晶界占比由316L/Q235复合板的0.79%增加至19%,高比例的∑3孪晶界对氢引起的裂纹萌生具有很高的抵抗力;同时,高比例的孪晶界破坏了大角度随机晶界的连续性,抑制了裂纹的扩展,有效地提高了复合板的抗氢性能。Abstract: This cost-effective stainless steel composite plate integrates the excellent hydrogen resistance of stainless steel with the high strength and wear resistance of low-alloy steel. Such composites offer a promising approach for developing commercial materials with superior resistance to hydrogen. However, the influence of the cladding microstructure on the hydrogen resistance of stainless steel/carbon steel composite plates remains poorly characterized. Consequently, base materials exhibiting contrasting deformation resistance (Q235 vs. 700L) were employed to control the cladding microstructure. This work characterizes the microstructure of stainless steel and carbon layers in 316L/Q235 and 316L/700L composite plates and evaluates its impact on hydrogen resistance. Results show that the 316L cladding layer in the 316L/700L composite plate preferentially recrystallizes, reducing its hydrogen embrittlement susceptibility index from 9.8% of 316L/Q235 composite to 5.9%. Recrystallization control elevated ∑3 twin boundary density in 316L cladding (316L/700L) from 0.79% of 316L/Q235 composite to 19%. This microstructure simultaneously impedes hydrogen crack initiation through twin boundary resistance and suppresses propagation by disrupting random grain boundary networks, collectively enhancing hydrogen embrittlement resistance.
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